Production of alkyl halides



Patented Aug. 6; .1

, momen s or A LKYL HhLIDES fLeanmf aandrussow, f Mannheim, and Gerhard,"Stein; budwigshafen on-theeithine, Germany, assignora. by mesne;assignments, to General j'Anlllneljih' Corporation. New York, N. Y f erm e 1 ma- 3 *NofD fa ins. mama ann 'becembp' J I 1935, Serial No.53,714. Divided and this apn giqn necemberf31,;1987,' Serial No.182,794-

' The present invention r'elate's to'the'manufacture and productiono'talkyllhalidesw This appli- 51935.- We have found that alkyl "halidesJandunsaturated organic compounds, can simultaneously be obtained in amanner-whichis veryjadvantageous industrially by treating organichalogenated l0 aliphatic carboxylic acids, nitrlles or esters which;

contain in the. molecule at least one halogen. atom and'one hydrogenatom attached to two adjacent carbon atoms with aliphatic alcoholsand/or ethers at elevated temperature in the f presence,

of a catalyst.

As halogen compounds oi the said suit-; able as startingmatenalsiheremay be men-f: tioned practically all halogenated. aliphaticcarboxylic acids, nitriles and estersin which the halogen atoms arealiphaticallycombihed and there may be employed not only monohalogenated aliphatic carboxylic acids, nitriles or esters but alsothose which contain two or more halogen atoms. For example there maybe'mentioned alphaand beta-chlorpropionic acid, chlorpropionic nitrile,chlorpropionic acid methyl ester,

-Suitable alcohols or ethers arei'or example the aliphatic, alicyclicand. aliphatic-aromatic j alco hols and/or their ethers as, for examplemethyl ethyl, propyl, butyL isopro'pyl, isobutyl and benzyl" alcohol orglycols and anyethers derived from the same. Ethers of such alcohola'asfor, example of vinyl alcohol, which are-notstable in the free state maybe employed according to this inven- 5 tion. If mixed ethers be employedinstead of simple ethers, corresponding mixtures otalkyl halides areobtained. P 1

. The reaction is-liable to proceed accordingto' the equations which aregiven by way otexamplez 40 1. CHr-CHz-COOH-l-CHaOH Y 1 lBeta-chlorpropionic methanol 1 acid I Y om=cnfcoon tomci+mo v ca andmethylchlcride 2. 2oHr-oHr-oooom+omoom I I 1 Beta-chlorpropionic-methyldimethyl ester ether acrylic methyl ester methyl i chloride Thecatalysts employed in thepresent'probess may be chosen from the groupconsisting of diflicultly reducible oxides and salts. Speciallyquantitative manner.

suitabl'ei'or this purpose are catalysts having a hydrating ordehydrating action. As catalysts cation has been divided out Irom our"copending application Ser. No. 53,714, filed. December 10,

. conium, thorium, aluminium sulphate, phosphates of aluminium, iron,cerium, bismuth, silver, and

uranium; also zinc tungstate or zinc chromate,

they :may be employed in admixture with one another or deposited oncarriers. In some cases the catalysts are particularly active in apeptized stateorin the form oi. gels.

Generally speaking the reaction may be carried out at any desiredpressure. If the alcohols and/or ethers used tend to form olefines, thistendency may be suppressed by using increased pressure. In this casepressures of up to about '50 atmospheres, advantageously up to about 20atmospheresare employed. Pressures amounting to atmospheres may howeverbe applied as well. The pro'cessds carried out at temperatures betweenand 500 C. advantageously "between 250 and 350 C. The most favorable'temperatures'lie between 260 and 320 C. In

some cases it is preferable to employ one 01' the initial materials inexcess, especially when working in a cycle. The reaction usuallyproceeds in a practically In=most cases, as for example in the-formationof methyl chloride, the reaction products may be very readily separatedfrom each other. a

As compared to the process so far employed for the manufacture of alkylhalides the process accordingto the present invention presents valuableadvantages. Thus, for example, in the usual chlorination of methane tomethyl chloride and methylene chloride, as well as in other directchlorinations of aliphatic compounds chloroform and carbon tetrachlorideare formed. When producing alkyl halides in accordance with the halo'gensplit of! from the saturated halogen compounds employed as startingmaterials is obtained not in the form of inorganic salts of only slightvalue but it is simultaneously rendered useful a for the formation ofindustrially valuable alkyl halides.

v Organic halogen compounds which as acids, esters, ketones or aldehydescannot withstand unchanged a treatment with alkalies, can thus beeasilyconverted into the corresponding unsaturated compounds.

V A mixture of 1 molecular proportion of betachlorpropionic acid and 1molecular proportion of methanol is vaporized and led over aluminiumoxide at 300 C. Acrylic acid and methyl chloride arev formed in verygood yields. Instead of aluminium oxide, thorium oxide may beused as thecatalyst;

, Example 2 A mixture of equivalent amounts oi beta-chlorpropionic acidmethyl ester and dimethyl ether is led in the vapor phase over aluminiumoxide at 290 C. Acrylic acid methyl ester and methyl chloride are thusobtained in'good yields.

" Example 8 A vaporous mixture of equivalent amounts ofalpha-chlorpropionic nitrile and methanol is led over aluminium oxide at300 C. A mixture of acrylic nitrile andmethyl chlorideis thusi'ormed ingood yields. j i

What we claim is: v

l. The process for the, production of alkyl halides and unsaturatedorganic compounds which comprises reacting oxygen compounds of the classconsisting of aliphatic alcohols and ethers with organic halogencompounds selected from the class consisting of aliphatic carboxylicacids and carboxylic acid esters and which contain in the molecul'e atleast one halogen atom and one hydrogen atom attached to two adjacentcarbon atoms at from to 500 C. in the presence of a solid, dehydratingcatalyst.

2. The process for the production of alkyl halides and unsaturatedorganic compounds which comprises reacting oxygen compounds of the classconsisting of aliphatic alcohols and ethers with organic halogencompounds selected from the class consisting of aliphatic carboxylicacids and carboxylic acid esters and which contain in the molecule atleast one halogen atom and one hydrogen atom attached to two adjacentcarbon atoms at from 250 to 350 C. in the presence of a solid,dehydrating catalyst.

3. The process for. the production oi! alkyl halides and unsaturatedorganic compounds which comprises reacting oxygen compounds of the classconsisting of aliphatic alcohols and etherswith organic halogencompounds selected from the class consisting of aliphatic carboxylicacids and carboxylic acid esters and which contain in the molecule atleast one halogen atom' and one hydrogen atom attached to two adjacentcarbon atoms at from 150 to 500 C. in the presence which comprisesreacting'oxygen compounds of the class consisting of aliphatic alcoholsand ethers with beta-chlorpropionic acid at irom 150 to 500 C. in thepresence of a solid, dehydrating catalyst. V

6-. Theprocess for the production of alkyl halides and unsaturatedorganic compounds which comprises reacting oxygen compounds 01" theclass consisting of aliphatic alcohols and ethers withbeta-chlorproplonic acid 'methyl ester at from 150 to 500 C. in thepresence of a solid, dehydrating catalyst.

LEONID ANDRUSSOW. GERHARD STEIN.

